A member of an oligarchy; someone who is part of a small group that runs a country.
A very wealthy business owner who wields political power.
A protoplanet formed during oligarchic accretion.
A person who rules or governs; someone or something that exercises dominion or controlling power over others.
A (usually rigid), flat, rectangular measuring or drawing device with graduations in units of measurement; a straightedge with markings.
To beat with a ruler (as a traditional school punishment).